Throwing the weight issue out of the way, how big could we make a telescope before the light from the center would be too quick for the light from the edges to travel to the focuser and make an image distorted? Or could this even be an issue and I am just making a fool out of myself?

How about the size of the moon. We actually used it to observe the sun with I think the Hubble, for the Venus transit.

So the moon is the reflector and the Hubble the eyepiece.

I have a design, carved into the side of a mountain thats a mile in dia.

Very interestingconcept! But of course, you would have to have everything aligned perfectly. And if you messed your focal length up by a few nanometers you could have your focal point 100 miles too far or too close. But in theory, it would work.

No, if you messed up your focal length by a few nanometers, your focal point would be only a few nanometers out.

AIUI, the use of the moon during the Venus transit was not for imaging - rather it was to allow a spectrographic analysis of the diffuse reflected light so that any changes due to atmospheric absorption in Venus's atmosphere could be measured.

Regarding imaging, there is no upper limit to the size a true, perfect paraboloidal mirror. It will phase all light perfectly together at its on-axis focal point, whether its aperture is 2 meters or 2 light-years. Interesting issues come up for a 2 light-year diameter mirror, however. You'd have to refocus on nearer stars relative to, say, quasars. That would add in a little spherical aberration. You'd also have to be careful at or near focus, as the full energy radiated from the star toward the 2 light-year paraboloid would be present (neglecting reflection losses, of course)